Fix AzureAttestationToken method to return nil instead of EmbeddedAttestation (#442)

Signed-off-by: Sammy Oina <sammyoina@gmail.com>

cmd/agent/main.go

@@ -192,11 +192,21 @@ func main() {
 		return
 	}
 
-	azureAttestationResult, azureCertSerialNumber, err := azureAttestationFromCert(ctx, cvmGrpcConfig.ClientCert, svc)
-	if err != nil {
-		logger.Error(fmt.Sprintf("failed to get attestation: %s", err))
-		exitCode = 1
-		return
+	if ccPlatform == attestation.Azure {
+		azureAttestationResult, azureCertSerialNumber, err := azureAttestationFromCert(ctx, cvmGrpcConfig.ClientCert, svc)
+		if err != nil {
+			logger.Error(fmt.Sprintf("failed to get attestation: %s", err))
+			exitCode = 1
+			return
+		}
+		eventsLogsQueue <- &cvms.ClientStreamMessage{
+			Message: &cvms.ClientStreamMessage_AzureAttestationResult{
+				AzureAttestationResult: &cvms.AzureAttestationResponse{
+					File:             azureAttestationResult,
+					CertSerialNumber: azureCertSerialNumber,
+				},
+			},
+		}
 	}
 
 	eventsLogsQueue <- &cvms.ClientStreamMessage{
@@ -208,15 +218,6 @@ func main() {
 		},
 	}
 
-	eventsLogsQueue <- &cvms.ClientStreamMessage{
-		Message: &cvms.ClientStreamMessage_AzureAttestationResult{
-			AzureAttestationResult: &cvms.AzureAttestationResponse{
-				File:             azureAttestationResult,
-				CertSerialNumber: azureCertSerialNumber,
-			},
-		},
-	}
-
 	if err := g.Wait(); err != nil {
 		logger.Error(fmt.Sprintf("%s service terminated: %s", svcName, err))
 	}

pkg/attestation/emptyprovider.go

@@ -22,7 +22,7 @@ func (e *EmptyProvider) VTpmAttestation(vTpmNonce []byte) ([]byte, error) {
 }
 
 func (e *EmptyProvider) AzureAttestationToken(nonce []byte) ([]byte, error) {
-	return cocosai.EmbeddedAttestation, nil
+	return nil, nil
 }
 
 func (e *EmptyProvider) VerifTeeAttestation(report []byte, teeNonce []byte) error {